Checkerwork



Patented Maty 9,` 1933 UNITED STATES JOHN P. GRILLI, OF CHICAGO, ILLINOIS i CHECKERWORX Application led J'une 18,

This invention relates to a new and improved checkerwork for regenerators, and more particularly to checkerwork especially adapted for use in connection 'with hot blast stoves of the types used with blast furnaces, used in the production of pig iron.

Hot blast stoves or the like consist .of

shells which are filled with brick checkerL work, the function of the brick being to absorb the heat from theproducts of combustion of from 20% to 40% of the top gases from the furnace, which are cleaned before burning in the hot blast stoves, and to give up heat to the air to be used in running the furnace.

The eiiciency of a. hot blast stove, or similar regenerative apparatus .depends primarily upon the efficiency of the heat transfer. The heat transfer rate per square foot of heatingsurface depends upon the. hydraulic diameter of the flues, the mass velocity in the flues, the degree of turbulence of flow in the flues, the thickness of the brick in the flues, and the temperature differential between the brick and the gases i'n the filles. 'There have been constructed many types of so-called high efiiciency hot blast'stoves l' checkerwork, but as these checkerworks used large brick andwere of complicated geometric design, the cost amounted "from two to three times the cost of an ordinary hot blast stove.

These types of checkerwork brick also are subjected to large internal stress in the brick,

and this results in much spalling and cracking of the brick, and as the flues in these bricks are usually small, the spalling and cracking soon plugs up the iiues to the passage of gases. i

To overcome the high cost of complicated geometric shaped brick, andl other disadvantages, the checkerwork as shown in Patent 1,815,905, issued July 28, 1931, was invented, has been installed inseveral plants, and has given fair results from a heat transfer standpoint, but from a structural of View, lacks stability.

This is caused by the more rapid heating and cooling of the inserts which cause a point rapid Wear of the feather edge of the filler' 'faces of the bricks of the -a maximum exposed contact area o 1932. Serial No. 617,932.

lues formed by the flue bricks. It has also been found that in the alternate heating and cooling of the checkerwork, filler brick placed diagonally in the checker flue, will finally act as wedges, and cause misaligning of all the checkerwork which will result in making-the h'ot blast stove inoperative.

In flues in which the filler brick are arranged diagonally tllereacross, the bricks of the flues which prevent the fillers from turning is lost for. heattransfer purposes, for the reason that there will be an extended contact between the lateral faces of the lillers at the ends thereof and thel proximate flue'.

It is one of the objects of the present invention to overcome these vdifficulties and objections and to reduce to a minimum the so-called contact area between the filler bricks and the flue walls, thereby roviding f) the filler and brick for the gases.

In the accompanying drawing: l

Figure-1 is a view partly in vtop plan, part- 75 ly in horizontal section of acheckerwork constructed in accordance with the principles of this invention, and as taken on line 1 1, Figure 2. i

i Figure 2 is a detail, vertical sectional view 80 enings or flues 11 will be formed extending vertically through the chcckerwork. Each course of rectangular brick 10 is preferably laid so as to break joint with the-next adja cent courses.

T he numeral 12 designates a filler brick 'i which is shown having two vertical planes of symmetry and is of a considerably larger ,diameter 1n cross, section' in one direction than in a transverse direction, so as to produce a filler brick which is comparatively thin'with respect to its width, and this brick 10 is of a size to extend entirely across the opening 11 inthe checkerwork so as to contact with opposite walls of the opening and so that the sides 13 are spaced from the opposite walls of the flue opening 11. The narrower vertical faces or sides of the brick are cut away or recessed as at 14 to provide each with a channel whichA extends for the entire length of the brick and opens through the ends thereof. The walls of the recesses 14 preferably converge from the outer edges of the brick inwardly and meet at points spaced a considerable distance from the transverse center of the brick so as to form clearly defined substantially sharp or feather edges 16 extending for the entire ylength of the brick.

displacemen symmetry corresponding i Vminimum contact with the .walls of the flue` Tho bottom of the brick is recessed as at 17 and the width of the recess on the major axis of the brick is only slightly greater than the width of the brick on its minor axis, so that when the brick 12 are superposed, the top of the lowermost brick will enter the recess 17 of the next adjacent uppermost brick and Will form an interlocking or interengaging means between the bricksto hold them against relative lateral The bricks thus constructed are superposed within the ue openings `11 and the bricks are so arranged/that the plane of to the width of alternate bricks will intersect the corresponding plane of the next adjacent bricks 1n the same vertical series, and the bricks are of such 'a size that the edges 16 will form a openings 11.

The edges 16 also-serve the purpose of ypreventing the bricks from turning in. the

ue opening and the interlocking means between the bricks hold them against relative di lacement within the flue openings.

'Srphese filler' bricks afford an increased heating surface together withy an increased' volume of heat absorbing material per unit ofcheckerwork volume, and it will be manifest that the ller brick not only. divides the flue opening 11.A into smaller fines, but the recessed portions 14 will form clearly defined flues and being arranged in stagger'ed relation with respect to each other, will cause an increased turbulence of the gas within the lues .while'lowing therethrough.` 1

Each of the brick is so designed that four lines of contact only will beV formed with the vertical walls of the checker iues, therewalls vby preventing the loss of the corners, as is the case with "diagonally arranged iiller brick.-

In the preseninvention the filler brick divides the flue area into smaller tlues which have a much smaller hydraulic diameter,

thecreof, that is by the projection of the end of one of the bricks into the recess 17 of the next adjacent brick, and furthermore the illl er brick constructed and arranged as herein shown, asslst 1n braclng the rectangular lbrick 10 and assists in maintaining the uniformity of the vertical lues,l

While the preferred form of the inven-l tion has been herein shown and described, it is to be understood that various changes may be made in the details of construction and in the combination and arrangement of the several parts, within the scope of the claims, without departing from the spirit of this invention. j x

What is claimed as new is v 1. A checkerwork construction, comprising a plurality of rectangular brick built up to form rectangular vertical lues, and a vertical lseries of iller bricks, each-of said filler bricks engaging the vertical flucs on four lines Vof contact.

2. A checkerwork construction, comprising a plurality of rectangular brick built up to form rectangular vertical lues, and a vertical series of filler bricks, eachv of said iller bricks engaging the vertical iiues on four lines of contact and remote from the corners of the flue. 1

3. A checkerwork construction, comprising a flue rectangulari in cross section, and a vertical series of filler bricks within and set at right an les to opposite faces of they vertical walls o the checker fines.

4. A checkerwork construction, comprising a lurality of rectangular brick built up to orm rectangular vertical flues, and a vertical and super osed series of filler bricks, the proximate en being interlocked against relative axial dis'- placement.

5. A checkerwork construction, consisting of flues, and interlocking means between the proximate ends of adjacent filler brick whereby adjacent nbrick are maintained against relative axial rotation. f

6. A checkerworky construction compriss of adjacent filler brick filler bricks within the flues, j

to forml rectangular vertical fines, anda rvertical Series of filler bricks within theflues, said filler bricks having a plurality of sides parallel to vertical walls of the check er flue, andv normal. to the other vertical 7. A checkerwork construction comprising a plurality of rectangular brick built up to form rectangular verticallues, a vertical series of iller brick within the Hue, and cooperating means ony said filler brick tov revent relative axial shifting on one anot er.

8. A checkerwork construction comprising a plurality of rectangular brick built up to form rectangular vertical Hues, and a vertical series of filler brick within the Hues,` said Hller brick being comparatively wide 'with relation to its thickness, the sides of the brick being parallel to the vertical walls of the checker Hues.

9. A checkerwork construction comprising Hues rectangular in cross section, and a series of filler brick within the Hues, said filler l brick lbeing comparatively wide with relation to its thickness, lthe 'vertical ends of each of the filler bricks being shaped to form planes at an angle of less than ninetydegrees from the contacting wall of the vertical Hue. l

10. A checkerwork construction comprising a plurality rof rectangular'-bricks builtup to form rectangular vertical Hues, and a series of filler brick within the Hues, said filler brick, each of said filler bricks engagfiller bricks having means engaging the Hue Walls ,remote from the corners thereof to prevent shifting, and vbeing installed in staggered relation to one another.

11. A checker work, comprising a Hue angular in cross section, and `a vertical series of ing only the vertical walls of the Hue remote from the corners of the Hue.

12. A checkerwork comprising ,a Hue an-v gular in `cross section, filler blocks in the Hue, portions of the periphery of said blocks being reduced to form laterally spaced clearly defined contact edges engaging only the vvertical walls of the Hue remote from the corners of the Hue.

.13. A checkerwork comprising Ia Hue angular in cross section, an a series of superposed filler brick within the Hue, eachof the bricks being comparatively thin with relation to the width of thebrick,` portions of the periphery of the thinner edges of the bricks being shaped to form spaced clearly Arip'hery of the thinner defined contact edges of a thickness con# siderably lemv than the thickness of the brick, extending lengthwise of the brick and engaging the walls of the Hue remote from the corners of the Hue, each of the bricks being so arranged that its greatest transverse horizontal axis will be disposed to intersect the greatest horizontal transverse axis`of each of the filler bricks thereabove and therebelow. .A

14. A checkerwork comprising a Hue an;

gular in cross section, a series ofsuperposed filler brick within the Hue, each of the brlcks being comparatively thin with relation to the width' of the brick, portions o f the peedges of the bricks being shaped to form clearly defined spaced I contact edges of a thickness considerabl less than the thickness of the brick exten ing lengthwise of the brick and engaging the Walls of the Hue remote from the corners .of

`of the two opposite the Hue, each of the bricks being so arranged that its lar er transverse horizontal axis will intersect t 1e greatest horizontal transverse axis ofeach of the filler bricks thereabove and interengaging means 7,0 between the proximate ends of vadjacent l bricks for maintainingthem against relative displacement. l v 15. A checkerwork comprising a vertical Hue rectangular in cross section, and a seriesl of superposed Hller brick in the Hue, each* of saidbricks being so channeled in oposite vertical faces -that resultant spaced pairs of edges thereof respectively -contact with each walls of the Hue and the lateral .faces of the brick being-spaced' from opposite `walls of the Hue, the bricks being shaped to form spaced clearly definedy feather edges extending lengthwise of the brick and forming contact with the Hue wall, Y said bricks being so superimposed that a vertical plane of symmetry of each brick 1s transverse to the corresponding plane of the next adjacent bricks thereabove and therebelow. A 16. A checkerwork comprising a vertical Hue rectangular in cross section, and a series of superposed filler brick in the Hue, each of said bricks being comparatively wide with relation to its thickness, the width of the brick beingrsuch that the longitudinaledges y of the brick will contact opposite walls of 1 the Hue, the thickness of the brick being' sch that the lateral facesof Vthe brick will be spaced from opposite' walls. o f the Hue, portions of the longitudinal edges of the brick on the greatest transverse axis being recessed to form clearly defined vcontact edges to engage the Huewall and extending lengthwise of thev brick and spaced laterally from each other to forma passage therebetween, said filler bricks being so super-k imposed that the greatest transverse diamel .ter of*v each brick will be transverseto .the greatest transverse diameter of the next ad- ]acent brick. s v 17. 'A checkerwork comprising a vertical Hue rectangular in cross section, a series of A t superposed filler brick in the Hue, said filler brick being comparatively wide with rela! tion to its thickness. each of said bricks having a greater transverse diameter of a I length that the edges of the brick will con! tact opposite walls-of the Hue, and a smaller transverse ldiameter of a size that the lateral faces of the brick on'the smaller diameter willbe spaced from opposite walls of the Hue, the end of the bricks on the greatest transverse diameter being shaped to form spaced clearlyj defined edges extending lengthwise of the brick and forming'contacts with the Hue wall,` said filler, bricks being so superposed that the greatest h0ri- :zontal transverse diameter of "each, brick will intersect the greatest horizontal trans-'r 13 asv y above and therebelow,

verse axis of the next adjacent brick therel and' interlocking means between the proximatelends of adp,-

cent bricks.

In testimony wheeof I name to this specification,

of June, A. D. 1932.

JOHN P. GRILLI.

have signed my on this 15th day 

